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3 years ago

A certain shade of blue has a frequency of 7.28×1014 Hz.

Chemistry

1 answer:

Lyrx [107]3 years ago

7 0

Explanation:

the enerfy of of one photon of this light is 4.85x10^-19 J

E= 4.85x10^-19 J

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Rationalize the following statements and give chemical reactions .

Dahasolnce [82]

Answer:

i do not no

Explanation:

sorry i do not known

8 0

3 years ago

Calculate the theoretical yield of aspirin obtained when 2.0 g of salicylic acid and 5.0 mL of acetic anhydride (density = 1.08

saw5 [17]

Answer:

The percent yield would be 73%

Explanation:

The balanced reaction for the obtention of acetylsalicylic acid (aspirin) is the following:

Salicylic acid + acetic anhydride → acetylsalicylic acid + acetic acid

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + C₂H₄O₂

According to the reaction, 1 mol of salicylic acid reacts with 1 mol of acetic anhydride to give 1 mol of acetylsalicylic acid (aspirin) and 1 mol of acetic acid.

1 mol aspirin (C₉H₈O₄) = (9 x 12 g/mol) + (8 x 1 g/mol) + (4 x 16 g/mol)

= 180 g

1 mol salicylic acid (C₇H₆O₃) = (7 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)

= 138 g

1 mol acetic anhydride (C₄H₆O₃) = (4 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)

= 102 g

The stoichiometric ratio is = 138 g salicylic acid/102 g acetic anhydride= 1.35

We have:

2.0 g salicylic acid

acetic anhydride = 5.0 mL x 1.08 g/mL = 5.4 g

The reactants ratio is = 2.0 g salicylic acid/5.4 g acetic anhydride = 0.37

0.37 < 1.35 , therefore <em>salicylic acid is the limiting reactant</em>.

Now, we use the amount of salicylic acid to calculate the theoretical amount of aspirin. For this, we know that 1 mol of aspirin (180 g) is obtained from 1 mol of salycilic acid (138 g):

theoretical yield= 180 g aspirin/138 g salycilic acid x 2.0 g salycilic acid = 2.61 g aspirin

actual yield = 1.9 g

Finally, we calculate the yield:

percent yield = actual yield/theoretical yield x 100

= 1.9 g/2.6 g x 100 = 72.8% ≅ 73%

6 0

3 years ago

Calculate the pH for the following solutions and indicate whether each solution is acidic or basic.

Nadya [2.5K]

The answer would for sure be 178 because acid & base make that amount so yea!! I’m talllyyy right

6 0

2 years ago

Read 2 more answers

When performing labratory experiments, which of the following items is ALWAYS necessary to use?

densk [106]

All of the the answers are are correct but a fume hood is more for if you are dealing with chemicals that can produce fumes the are deadly to people

3 0

4 years ago

Hello! I just need a little bit of help. I'm supposed to design an experiment on how reaction rates are determined and affected

alexandr1967 [171]

Get 3 cups of water at the exact same temperature, using the thermometer to check.
Label the cups as ‘whole’, ‘pieces’, and ‘crushed’
Next, get something to dissolve, in this case, polident. Take one of the polident tablets and break it into 4 pieces, and set it aside.
Take another polident tablet and this time put it into a different cup, and crush it. Set it aside.
Keep the last tablet whole.
Set up your stopwatch and drop the polident tablet that is whole in the cup labeled ‘whole’, starting the stopwatch at the same time.
Watch the cup and see when the tablet is fully dissolved, then stop the stopwatch.
Record the time in the table.
Repeat steps 6-8 for both the ‘pieces’ and ‘crushed’ tablets.

Hope this helps! Please let me know if you need more help, or if you think my answer is incorrect. Brainliest would be MUCH appreciated. Have a great day!

Stay Brainy!

− $xXheyoXx$

3 0

2 years ago